Potential impact of climate change on habitat suitability of Pacific saury in the Northwestern Pacific Ocean

This study assessed the potential impact of climate changes on the habitat of the Pacific saury in the Northwestern Pacific Ocean under various scenarios derived from the IPCC AR 6 report. Six environmental variables, namely sea surface temperature, sea surface salinity, sea surface height, dissolved oxygen, mixed layer depth, and net primary productivity, were used to estimate the habitat suitability index (HSI) using the yield density approach. Three periods were divided, namely historical (2001-2014), current (2015-2021), and future (2030, 2050, and 2100) to evaluate the climate change impacts on the Pacific saury. Latitudinally, the center of the saury suitable habitat area (SHA) was generally located around 43 – 44°N in the historical period with a slightly northward movement, shifted to 44.5 – 45.5°N in the current period, and moved to 45-46°N in most of future projections, except for SSP 1-1.9 (the lowest emission scenario). Longitudinally, the saury SHA center was distributed around 164.5- 166°E in the historical period with a slightly eastward movement, shifted to 166-168°E in the current period, then moved eastward for the scenario SSP 2-4.5, 3-7.5 and 5-8.5, and westward for the scenario SSP 1-1.9 and 1-2.6 in the future projections. The grid number of the saury SHA showed a gradually decreasing trend in the historical period and continuously decreased in the current period. In all future projections, the grid number also exhibit a decreasing trend to the lowest in 2100. In addition, the current saury SHA distribution is closely aligned with SSP 1-2.6 (low emission pathway).